Safety and Efficacy of Herceptin + Chemotherapy Further Supported by Studies Presented at Breast Cancer Conference

SAN ANTONIO (PROTEXT) - New advances in the study ofHerceptin(R) (trastuzumab), when used in combination with commonchemotherapies for the treatment of advanced (metastatic) breastcancer, were highlighted in two presentations at the 22nd AnnualSan Antonio Breast Cancer Symposium. Herceptin Plus Vinorelbine Combination Study ReportsEncouraging Results In a study led by investigators at Dana-Farber CancerInstitute, Herceptin and the chemotherapy agent vinorelbine havebeen used to treat 34 women with HER2-positive, advanced breastcancer. Most women in this study had previously receivedchemotherapy treatments for their breast cancer. "The response rate to date of over 70 percent is encouraging,particularly when considering that these women with breast cancerhave the more aggressive HER2-positive form of the disease," saidDr. Harold J. Burstein, a lead investigator on the study at Dana-Farber. "A gratifying aspect of the study is that the treatmentshave, so far, been very well tolerated with relatively few sideeffects." Dr. Eric P. Winer, head of breast oncology at Dana-Farber andsenior investigator for the study, stated that, "while the datapresented today are encouraging, they are still preliminary. Weare continuing to care for women on this study, and arecautiously optimistic that this will prove a valuable regimen fortreating advanced breast cancer." Herceptin and Weekly Taxol Therapy Appears to Show HigherResponse Rates in HER2-Positive Patients In a separate study, preliminary analysis showed that amongthe 62 evaluable patients, Herceptin and weekly Taxol combinationtherapy increases response rates in HER2-overexpressingmetastatic breast cancer patients compared to non-HER2overexpressing patients. Francisco J. Esteva, M.D., assistantprofessor of medicine at The University of Texas M. D. AndersonCancer Center reported that these preliminary results of HER2-positive patients receiving weekly doses of Herceptin plus Taxolhad a 78 percent response rate compared to a 50 percent responserate in non-HER2 overexpressing patients. The highest responserates were noted in patients whose tumours were HER2 positive bya combination of monoclonal and polyclonal antibodies.Fluorescence in situ hybridization was also a good predictor forresponse to weekly Taxol plus Herceptin. "This study highlights the importance of optimizing HER2testing methodology as a predictor for response to Herceptin-based therapy," said Dr. Esteva. Future trials are currentlybeing planned to further investigate the use of Herceptin andweekly Taxol in HER2-overexpressing and HER2 non-overexpressingpatients. HER2 and Breast Cancer HER2 is a protein produced by a specific gene with cancer-causing potential. This protein serves as a receptor for thegrowth hormones that circulate in the blood and influence therate of cell growth and differentiation. Under normal conditions,there are two copies of the gene that produces HER2. Researchersdiscovered that sometimes this gene is amplified, resulting inmore copies than are needed. This amplification, in turn,triggers an overproduction, or overexpression, of the growth-factor receptor HER2. Excess amounts of HER2 lead to the uncontrolled cellulargrowth that is the hallmark of cancer. Approximately 30 percentof women with breast cancer overexpress HER2. Because HER2overexpression is related to poor overall prognosis with fasterrelapse time at all stages of breast cancer development, it isimportant that patients diagnosed with breast cancer are testedfor their HER2 status. Roche Pharmaceuticals Herceptin was discovered and developed by Genentech, Inc., aleading U.S. biotechnology company in which Roche owns a majorityshare. In July 1998, Genentech granted Roche exclusive marketingrights for Herceptin outside the United States. Roche andGenentech will also work together in a joint global developmentprogram for other solid tumours, such as non-small cell lung andcolorectal cancers. Roche, headquartered in Basel, Switzerland, is a worldwideleader in research-based healthcare with principal business inpharmaceuticals, diagnostics, vitamins, and fragrances andflavours. Roche discovers, develops and markets prescriptiondrugs in key therapeutic areas such as diseases of the nervoussystem, virology, infectious diseases, oncology, cardiovasculardiseases, inflammatory and autoimmune diseases, dermatology,metabolic disorders and respiratory diseases. ots Original TextService: Roche Pharmaceuticals Internet:http://www.newsaktuell.de Contact: Kim Callahan, +1-212-453-2425, callahak@fleishman.com, or Robin Gallon, +44-1235-554627,r.gallon@synapse-uk.com, both of Fleishman-Hillard for Roche

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